Strap stretching tool



"H. c. BRISTOLL Er AL May 10, 1938.

' STRAP STRETCHING TOOL Filed June 25, 1936 2 Sheets-Sheet l H4RP/S0N GER/57791.1, ROBERT VSANFORD HOWARD C. DOOLITTLE' May 10, 1938. Bms-roLL ET AL 2,117,015

STRAP STRETCHING TOOL Filed June 25, 1936 2 Sheets-Sheet 2 Fig.4

gwue/wbo'b MPH/JON 6. BRISTOLL ROBERT VJANFORD HQWARD G170 LITTLE Patented May 10,

2,117,015 srmr sranrcmnc TQOL Harrison 0. Bristoil, New Britain, Robert V. Sanford, Hartford, and Howard C. Doolittle, New Britain, Conn., assignors to The Stanley Works, New Britain, Court, a corporation of Connecticiit "Application June 25, 1936, Serial No. 87,144

, 12 Claims. ((1254-46) This invention relates to a device for stretching straps or bands about packages, boxes, or other articles.

, The aim of the invention is to provide a more simple and effective strap stretching tool which is relatively light in 'weight, may be easily handied, and conveniently operated; which is very simple and compact in construction, and capable of being constructed at low cost; and which is strong and durable. t

A further aim of the invention is to provide a tool of this character with an improved arrangement whereby the overlapping strap ends may be held during the tensioning operation a sufficient distance away from the package being strapped to permit of the positioning of the seal on the strap ends and accommodating the jaws of a sealing instrumentality during the sealing operation, this arrangement being of particular advantage when applying the straps to rounded surfaces.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

Our invention accordingly consists in the features of construction, combination of elements,

, and arrangement of parts which will be exemplified in the construction hereinafter set forth and the scope of the application which will be indicated in the appended claims.

In the accompanying drawings illustrating one embodiment of our invention and wherein like parts are indicated by like numerals:

Figure 1 is 'a side elevation of our invention showing its application to tensioning a strap 35 around a box or similar object having a flat face;

Fig. 2 is an enlarged fragmentary sectional view illustrating the ratchet feed mechanism associated with the tensioning device;

Fig. 3 is an enlarged fragmentary plan view 40 showing the forward clamping mechanism and the strap supporting means associated therewith;

Fig. 4 is a view taken substantially along the lines H of Fig. 3 and showing a transverse section through the forward clamping mecha- 45 nism;

Fig. 5 is a view taken substantially along the lines 5-5 of Fig. 3 and showing a longitudinal section through the forward strap supporting members and associated parts; and

Fig. 6 is a fragmentary .view of our invention illustrating its application to tensioning a strap about an article having a rounded contour.

In accordance with our invention, we have provided a strap stretching too] including a frame 55 i2 having a rearwardly extending handle I3 generally aligned longitudinally of the tool, but inclined upwardly and rearwardly as later de-- scribed. A strap lock in the form of a dog It cooperating with a laterally extending lug I5 is carried by the frame for the purpose of securing one end of a. strap I0 tothe frame; The frame has a longitudinal bore extending axially through the handle and slidably accommodating a rack bar I 6, the forward end of which is provided with a head I! having a foot [8 with which -cooperates a strap lock in the form of a dog I9 for securing the other end of the strap to' the head.

An operating hand lever 20, pivotally connected to the body through a shaft 2i extending transversely through the frame, is ratchet connected to the rack bar so that when the hand lever is operated, the rack bar is axially moved and the frame and head move relatively away from each other to pull the respective forwardly and rearwardly projecting strap ends Illa and lllb in opposite directions and tension strap l0 about an article being handed. A supporting foot 22 is located beneath frame I 2 substantially in the plane of foot i8 to aid in supporting the tool when employed on a flat surface. As shown in Fig. 1, foot 22 is so positioned with reference to foot i8 that the tool may be supported at a slight angle whereby an operator will have ample room for his fingers between the handle and the article being banded.

. The operative connection between lever 20 and the rack bar It includes a pinion 23 journalled on shaft 2| and meshing with the teeth of the rack bar. As shown in Fig. 1, the teeth on the rack bar terminate in spaced relation to the ends of the bar, thereby limiting the maximum extent of rack bar movement in both directions. Carried by lever 20 adjacent to pinion 2| is a driving pawl 24 pivotally mounted on a transverse pin 25 supported in a forked portion of the forward end of the lever and spring pressed into driving engagement as shown. The nose of pawl 24 is so arranged that when the lever is angularly moved in one direction, rearwardly and downwardly in the present instance, the pinion is rotated (clockwise in Fig. 2) to move the rack bar outwardly from frame l2, and when the lever is swung in the opposite direction (upwardly and forwardly) during an inoperative stroke, pawl 24 will ratchet or slide over the pinion teeth without remaining in driving engagement therewith.

For the purpose of preventing retrograde movement of the rack during the inoperative stroke of the lever and to lock the rack against movement into the frame during a strap tensioning operation, a pair of holding pawls 26 and 21 are provided. These pawls are pivotally supported on a transverse pin 28 supported by the frame and are spring pressed into engagement with the pinion teeth. These holding pawls are provided with noses arranged to prevent counter-clockwise rotation of pinion 23 (with rei'ercnce'to Fig. 2) so that when the pinion is rotated in a clockwise direction by lever 28 and pawl 24. the pawls 26 and 21 will'ratchet over the pinion teeth. As shown in Fig. 2, the noses of pawls 26 and 21 are preferably offset slightly from each other to minimize any retrograde rack movement during a tensioning operation.

. After the overlapped strap ends are, sealed together. it is desirable to quickly remove the pawls from operative pinion engagement so that the rack may be retracted into. the frame to any desired position. To accomplish this, the upper ends of the driving and holding pawls terminate in the respective ears 24'. 26C and 21' which are so positioned with relation to each other that whenever hand lever 20 is shifted to the full extent of .its inoperative movement. these ears will engage, causing all of the pawls to pivotally swing out of pinion engagement. At this time,

the pinion is free to rotate, and the rack l6 and head 11 may be manually positioned wherever desired with respect to the frame.

Referring now to the strap locks, dog 14, which is journalled at its upper end on a projecting portion of pin 28, is provided with a serrated bottom face forming a multiplicity of closely spaced teeth which are urged towards strap supporting foot i5 by a spring 38 compressively received between the dog l4 and the frame. The upper end of the dog terminates in a parti-cylindrical surface coaxial with pin 28 and located beneath an overhanging flange 32 laterally projecting from the frame. The underside of the flange has a curved face coaxial with pin 28 and engaging with the upper end of dog 14 to offer a support therefor independent of pin 28. Dog 14 extends somewhat rearwardly and in angular relation to a vertical plane including the axis of pin 28 so that whenever the strap end l0b is inserted between the dog and foot IS, a tensioning pull on the strap end towards head i1 will aid in more firmly clamping the strap in position. The strap end iiib may be easily prelocated or disengaged by pulling it towards the handle end of the frame whereupon dog l4 may be swung out of operative position.

The forward strap lock is pivotally supported within the head, I1 which in turn is held on a reduced portion 33 at the forward end of the rack bar by means of a screw 34. A shoulder 35 at the rearward end of head [1 engages the flat top face of the rack bar to prevent relative angular movement between the head and bar. The forward strap lock is made in the form of an integral clamping dog l9 having a relatively long, laterally extending, cylindrical shank 36 from one end of which depends an arm 31 terminating at its lower end in a laterally projecting flange 38 having a serrated bottom face providing a multiplicity of strap engaging teeth adjacent the upper face of foot l8. Head i1 is provided with a relatively long, transverse bore 40 within which the shank 36 is journalled, and the right-hand end of said bore (Figs. 1, 3, and 4) terminates in a recess 4| somewhat triangularly shaped in vertical section and having a bottom face merging with the top of foot l8 and an upper curved face 42 coextensive with bore 40. This recess receives depending arm 31 and is of such size as to permit of its angular movement therein. The upper curved face 42 cooperates with bore 48 and in effect forms a continuation thereof, so that a relatively long bearing is provided for the front .position and towards the upper face of foot 13. A spring 43 within recess 41 and compressively received between head l1 and arm 31 tends to maintain dog F9 in a strap grippingposition. It is noted that the flange 33 is relatively broad in the direction of the lengthof the tool and is relatively thin in vertical direction, this arrangement being-oi advantage in that the flange isstrong enough to take the strains exerted thereon, while at the same time the. overlapping strap ends forwardly of the head are closely adjacentto each other, thus allowing a seal to be readily placed thereabout. During the operation of tightening the strap, there is a tendency for the tool to swing or pivot forwardly and upwardly about the "forward edge of the head l1, and in order to prevent this, we provide, on the head and rearwardly of the flange and at a plane somewhat above the upper surface of the flange, a lug 44. The overlying strap end is required to pass beneath this Dog I9 is prevented from axial movement in one direction by the engagement of the arm 31 against the side of the head. and in the other direction by means of opposed shoulders 48' and 41, respectively, on the reduced end 33 of the rack bar and .on shank 36. The shoulder 41 on the shank is provided by a groove 46 cut transversely within the lower side of the periphery of shank 36 and intermediate of its ends. This groove has a curved contour adapted to loosely overlie the top peripheral face of reduced portion 33 on the end of the rack bar and terminates at its lefthand end in the substantially vertical shoulder 41, as shown in Fig. 4. Shoulder 41 engages the vertical shoulder 48' formed by recessing or stepping the top of reduced portion 33, as at 43.

It will be noted that the two strap locks are so positioned with relation to each other that the forwardly extending strap end Illa may be inserted between flange 38 and foot i3 so that a considerable extent thereof projects forwardly of head 11, and the rearwardly projecting end llib of strap l0 may be located in superimposed substantially aligned relation to end Illa and extend over flange 38 beneath the lug 44 and thence between dog l4 and foot 15. vAn operative movement of the handle 20 at this timewill tend to move the strap locks relatively away from each other and tension the strap ends about the article being banded. Due to the fact that dog I! angularly extends forwardly and dog l4 angularly extendsrearwardly, the tensioning operation will tend to cause said dogs to more firmly clamp into strap gripping engagement and thereby prevent tendency of strap slippage. As shown in Fig. 1 which illustrates the application of our tool to tension a strap around an article. such as a box having a flat upper face, the forwardly projecting strap end Ilia normally passes beneath foot 22, but it will be appreciated that our device may be operated with said strap end passing over foot 22 if desired.

Our dc. vice is also constructed in such manner that it may also be easily applied to stretching the strap member In about articles of any shape and particularly about a bundle of merchandise having a curved outer surface, such as the bale A shown in Fig. 6. To accomplish this, the lefthand side of head ll (Fig. 4) is provided with a laterally projecting cylindrical boss ill concentric with bore 40 and having a strap supporting member 5| journalled thereon for pivotal movement. The strap supporting member may comprise a longitudinally extending arm 52 journailed at one end on boss 50 and having a laterally projecting arm 53 at its outer end adapted to underlie the overlapped strap ends when desired. Arm 53 is preferably provided with a rounded upper face soas to provide a line contact between the arm and lower strap end and thus facilitate stripping of the tool from the package after the stretching and sealing operations have been completed. The free end of the arm 53 is tapered,

by a screw) and arm 52 to frictionally maintain the strapsupporting member in any desired position. It will thus be appreciated that in the event that our invention is employed for applying a strap about a curved surface, the overlapping u strap ends may be cooperatively supported between arm 53 and foot l8 and in spaced relation to the article being handed so that an open seal may be properly positioned therebetween on said strap ends and a sealing tool may be easily applied to firmly secure the seal in place. In the event that it is not desired to use the strap supporting member 5|, it will be evident that it may be easily swung to an inoperative position as shown in Fig. 1, and spring 55 will tend to maintain it in said position. Furthermore, when tensioning a strap about a box or other article having a flat face, it will be appreciated that member 5! may or may not be employed, as desired.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention-could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

We claim as our invention:

1. In a strap stretching tool, a strap supporting foot, a strap tensioning mechanism associated therewith and arranged to exert a pull in opposite directions on the overlapped ends of a binding strap, and a strap supporting member adjustably connected to said foot, said member having a laterally projecting arm cooperating with the foot in maintaining a short portion of the overlapped strap ends spaced from an article being handed.

2. In a strap stretching device, a frame, a strap supporting foot movably associated therewith, a strap tensioning mechanism associated with said foot and frame and adapted to pull the overlapped ends of a binding strap in opposite directions to tension the strap about an article, and a member pivotally connected to the foot, said member having a laterally extending strap supporting portion located in spaced relation to the foot and cooperating therewith to support the overlapped strap ends in position for convenient application of a sealing tool.

3. In a strap stretching device for tensioning a strap about an article, a frame, a strap sup-v porting foot movably associated with the frame, gripping means associated with the frame and the foot and arranged to respectively clamp the opposite ends of a flat metal binding strap in superimposed relation, means causing .a relative movement of said foot and frame to tension the strap, and a forwardly projecting strap supporting member pivotally secured to said foot and arranged to maintain a short length of the overlapped strap portions in spaced relation to the article during a binding operation.

4.In a strap stretching tool for binding an article, a movable head having a foot adapted to support a pair of strap ends in overlapped relation, a gripping member on said head resiliently urged towards said foot and into locking engageber having alaterally projecting arm disposed substantially parallel to and in spaced relation with the foot, said arm being adapted to engage the article and cooperating with the foot to support the overlapped strap ends in spaced relation to the article.

5. In a strap stretching device, a forward strap supporting foot, a rearward strap supporting foot, gripping means associated with each foot and arranged to respectively clamp the opposite ends of a flat metal binding strap in superimposed relation, means to cause a relative movement of said feet away from each other to tension the strap about an article in binding relation, and a strap supporting member pivotally mounted on the forward foot and having a laterally projecting arirr located in spaced relation to the forward foot and adapted to cooperate therewith in supporting a predetermined extent of the overlapped strap portions above the article being banded irrespective of its shape.

6. In a strap stretching tool, a frame, a fixed thereoffsaid support including a laterally projecting arm-adapted to support the overlapped strap ends in contacting relation with each other and to cooperate with the movable foot so that said contacting strap ends may be easily secured together with a sealing tool irrespective of the shape of the article being banded.

'7. In a strap stretching tool, a movable memher having a laterally projecting foot adapted to support a pair of overlapped strap ends, a gripping dog supported by said member and pro vided with a laterally projecting flange adapted to clamp the lower strap end to the foot, a boss laterally projecting from said member, a strap support journalled on said boss, and resilient means frictionally restraining said movement, said support including a laterally projecting arm engageable with the article being bound and cooperating with the foot to support a portion of the overlapped strap ends in contact with each other and in spaced relation from said article.

8. In a strap stretching tool, a strap gripping mechanism comprising a member-having a laterally projecting strapsupporting foot and a relatively long bore; a single piece strap gripping dog having a shank journalled in said bore, a downwardly extending arm at one end of said shank, and a relatively broad and relatively thin strap gripping flange projecting laterallyfrom the lower end of said arm and located above the foot; a multiplicity of teeth on the bottom-of the flange, and a spring located between the memher and movable arm tending to swing the armand urge the teeth towards said supporting face into strap gripping position.

9. In a strap stretching tool, a head having a relatively long transverse bore provided with a curved surface atone end concentric with and forming a continuation of the surface of the bore,

said head having a strap supporting foot posltloned below and extending beyond said surface,

a single piece strap gripping dog having a shank portion journalled in said bore, 9. depending arm at one end of the shank portion'and above said foot, a relatively broad and thin strap gripping flange laterally extending from the lower end of said depending arm and overlying said foot,

the upper end of said arm. having a curvedface slidably bearing on said surface, said depending arm being angularly disposed to a plane perpendicular to the foot and including the axis of the shank; resilient means tending to urge the relatiOn, and means axially positioning the shank in said bore and vpermitting rotary shank movement. 1 r

10. The combination ina strap stretching tool of a frame, a 'rack member slidably movable therein and having a reduced portion on its forward end, a head mounted on said reduced portion and having a laterally projecting foot provided with a strap supporting face, a strap gripping dog having a shank journalled in the head for pivotal movement and a strap gripping portion in overlying relation to said foot, the shank having a transversely grooved portion terminating in a shoulder. and a shoulder on the reduced portion of the rack, said shoulders eng'r ging each other and cooperating to prevent removal of the strap gripping dog from the head.

said reduced portion and terminating at one side in a depending. shoulder parallel to said longitudinal bore, and an upwardly extending shoulder on said reduced portion, said shoulders cooperating to prevent removal of the gripping dog from the head without restraining pivotal movement of the dog.

12. A strap stretching tool comprising a frame having a rearwardly extending handle and a bore extending axially through said handle, said body having a supporting surface on its under side, a rack bar mountedfor longitudinal movement in said bore, a head on the forward end of said rack bar and having a bottom supporting surface disposed in the plane of said supporting surface on the frame, strap gripping members respectively carried by said body and head and through which a strap is stretched when the head and frame are relatively moved apart, and an operating lever ratchet-connected to said bar and pivoted to said body forwardly of said handle and adapted to swing above the handle, said bar and handle being inclined rearwardly and upwardly away from the plane including the bottom surfaces of said frame and head.

' HARRISON C. BRISTOLL.

ROBERT V. SANFORD. HOWARD C. DOOLI'I'I'LE. 

